1. Field of the Invention
This invention generally relates to an actuator that provides a user with tactile information such as vibration or the like.
2. Description of the Related Art
In various electronics information devices that include computer devices, mobile information devices, and the like, there is known a technique of giving information to an operator with the use of an actuator that provides tactile or haptic information such as vibration or the like. It is desirable that the actuator that provides the tactile information be downsized as much as possible, in consideration that such actuator is built in a device. As a downsized actuator that provides the tactile information, for example, there is known the actuator in which a movable element moves in a two-dimensional direction, as disclosed in Japanese Patent Application Publication No. 2000-330688 (hereinafter, referred to as Document 1) and Japanese Patent Application Publication No. 2004-145748 (hereinafter, referred to as Document 2). The actuator disclosed in Document 1 includes: a stator of a plane plate provided with multiple magnets formed in a plane shape and disposed on a substrate; and a sensitive portion serving as a movable element that retains multiple coils commonly to oppose the magnets. The actuator is driven in a two-dimensional direction of x-axis direction and y-axis direction crossed at right angles at the sensitive portion, by making the current flow across the coils to control the coils. The actuator disclosed in Document 2 includes: a stator of a plane plate provided with multiple magnets formed in a plane shape and disposed on a substrate; a movable element that retains multiple coils commonly to oppose the stator; and a guide mechanism that movably guides the movable element in a two-dimensional direction of x-axis direction and y-axis direction.
It is to be noted that the above-described actuators have a structure in which the coils are disposed at only one side of the permanent magnets of a plane shape. Therefore, the use efficiency of the flux of the permanent magnets is low, and it is difficult to effectively increase the thrust force of the actuator. In addition, the above-described actuators just perform the translational movement in x-axis direction and in y-axis direction, thereby limiting the tactile information that can be provided to the above-described movement.